Lab Exercise 6a-2

Connective Tissue

Nervous

Muscle

Classification of connective tissues

Connective Tissue

Connective tissue proper Fluid connective tissue Supportive connecting tissue

Connective tissues

Connective tissue proper Loose connective tissue

Areolar Adipose Reticular

Dense connective tissue Dense regular Dense irregular Elastic tissue

Fluid CTBlood

Supporting CTsCartilageHyaline cartilageElastic cartilageFibrocartilage• Bone

Areolar tissue

A loose CTP

Areolar

Areolar: what to look for

Fibroblasts Collagen fibers Elastic fibers Mast cells and macrophages

Found? Throughout body, under dermis, divides skin from underlying tissues

Fibroblasts

Resting fibroblasts typically have so little cytoplasm that the cells appear, by light microscopy, as "naked" nuclei

Fibroblast

Adipose tissue

Another lose CTP (note nucleus)

Adipose: what to look for

Lots of cytoplasm Slim nuclei pushed off the side

Found? You know where

Reticular tissue

The third type of loose CTP

Reticular tissue

Reticular: what to look for

Reticular fibers (network)

Found? Internal framework in many sort organs (liver, spleen) supporting the parenchyma

Dense CTP

Dense regular – strength in one direction Dense irregular – strength in all directions Elastic tissue - pliable

Dense regular

Dense regular: what to look for

Thick parallel bundles of collagen Small fibroblasts in between bundles

Found? Tendons, ligaments, deep fascia.

Dense irregular

More dense irregular

Dense irregular: what to look for

Mesh of collagen fibers (irregular looking) Interspersed fibroblasts

Found? Dermis of skin, periosteum, perichondrium

Elastic tissue

Elastic tissue: what to look for

Elastic fibers (instead of collagen fibers) in large bundles

Fibroblasts

Found? Between vertebrae, in blood vessel walls (underneath endothelium)

Fluid CT

Blood

Blood: what to look for

RBCs White blood cells (darker): monocytes,

lymphocytes, granulocytes Platelets

Supportive CT

Cartilage – gelatinous, padding Hyaline cartilage Elastic cartilage Fibrocartilage

Hyaline cartilage

Glasslike because fibers not visible

More hyaline

There are collagenous and elastic fibers lying in the cartilage matrix but they are invisible because their “refractive index” is the same as that of the matrix (like cornea)

More hyaline

Hyaline cartilage

Hyaline

Hyaline cartilage (lavender matrix), with perichondrium (pink) outside it. The latter is a dense regular collagenous CT. Cartilage cells = chondrocytes, and they are lying in the lacunae.

Hyaline cart.: what to look for

Chondrocytes and lacunae No visible fibers Where? Most joints, nasal septum

Elastic cartilage

Elastic Cartilage

Elastic cart: what to look for

Many elastic fibers in matrix Chondrocytes in lacunae May be stacked up

Fibrocartilage

Fibrocartilage: what to look for

Irregular, wispy collagen fibers Chondrocytes

Found? Intervertabral discs of spine, pads in knee joint

Supportive CT: Bone

Detail of lacuna, showing radiating canaliculi. Tissue fluid from the capillaries and connective tissue of the Haversian canal can seep through these spaces and channels, bringing nutrients to the stellate osteocytes residing there.

Bone: what to look for

Osteon (whole circular structure) Concentric lamellae (of matrix) Central canal (at center of lamellae) Osteoblasts Osteocytes in lacunae Canaliculi

Found? Bones!

Nervous tissue

Neuron smear Large, pyramidal cell bodies Long processes extending out

Nervous Tissue

Figure 4.10

3 Types of Muscle Tissue

Skeletal muscle: large body muscles responsible for movement

Cardiac muscle: found only in the heart

Smooth muscle: found in walls of hollow, contracting organs (blood

vessels; urinary bladder; respiratory, digestive and reproductive tracts)

Muscle Tissue: Skeletal

Long, cylindrical, multinucleate cells with obvious striations

Found in skeletal muscles that attach to bones or skin

Muscle Tissue: Skeletal

Figure 4.11a

Muscle Tissue: Cardiac

Branching, striated, uninucleate cells interlocking at intercalated discs

Muscle Tissue: Cardiac

Figure 4.11b

Muscle Tissue: Smooth

Sheets of spindle-shaped cells with central nuclei that have no striations

Found in the walls of hollow organs

Muscle Tissue: Smooth

Figure 4.11c

Exercises

Look at all slides Draw an example of each tissue on paper provided 11 connective tissues:

6 CTP (3 loose, 3 dense) 1 Fluid CT (blood) 4 Supportive CT (3 cartilage, 1 bone)

Neurons 3 Muscle tissues

SkeletalStriatedSmooth

Turn in on Thurs 10/25

7 drawings from 6a-1 Epithelia 15 Drawings from 6a-2 Connective+ Review sheet for lab 6a